I'm not sure where my 160 thermo came from, cityside garage installed it for me while they were troubeshooting the cooling issue a while back. I'd just call up Eric at AB and ask him for one.

Follow-up Post:

As a follow up to my fans cycling up and down, I've got the truck all back together and according to the VDO gauge the fans come on just under 180 degrees, and they kick off at about 170 I think (that's a little harder to tell on the gauge). That's just what the the 82C-77C switch listed by Hans is supposed to do (which is 180 on-170 off)

And happily, they are now cycling on and off which they never did in the past. Once good and warm, it does take quite a few minutes of running to get them off once they start, and only about a minute and a half of running at idle for them to come back on. I do wish they cooled faster which makes me think the stock setup is actually more efficient. But I'm tired of replacing viscous units, and now I get the bonus of being able to run with them off for deep water crossings. Plus I don't have the temperature control I have now with the stock viscous unit, it pulls air when it's ready too.

With the heat wave we've been having up here lately, I noticed that the fans are sometimes running while the truck is driving at speed, but that's only climbing up some long hills I've got here at highway speed, and the temp only creeps up to 180. Generally I can see the temp staying just below where the fans will kick on.